Removable bottom furnace



E. A. SMITH REMov'ABLE BOTTOM FURNAGE Filed. April 29, 1941 March l0, 1942.

Inventr- Ernest A. Smith,

s Attorneg.

Patented Mu. 1o, 1942 PATENT "o1-FICE 2,275,926 REMQVABLE BOTTOM FUBNACE Ernest A. Smith, General El New York Schenectady, N. Y., alsignorvto Company. a corporation of applicaties ssrn ze, im, sensi No. 390,93: f

'4 oisans. (o1. zes-4o) My invention relates `to furnaces of the elevator and removable bottom type whereby after the charge'in the furnace has had its temperature raised to the desired point with the bottom o`f the furnace in the closed position the bottom may be quickly moved to the open pomtion to Venable the chargeto be lowered into a quenching tank. It is the object of my invention j to provide an improved furnace of this type having simple and effective means for quickly mov- '10 ing the furnace bottom from one pomtion to the other. A further object of my invention is the provision of means for eifecting a horizontal translation movement of the furnace bottom and a vertical sealing movement thereof, the two movements being produced in succession by the continued operation of a single driving member.

My invention will be better understood from the following description taken in connection with the accompanying drawing and its scopey will be pointed out in the appended claims.

In the drawing Fig. l is an end view partly in cross section of a furnace involving my invention and Fig. 2 is a side view loi' the same with parts in cross section.

Referring to the drawing, I represents the side walls and top of the furnace, the same being supported in an elevated position by the structure 2. By way of illustration I have shown a charge within-the furnace comprising a series of plates 3 which are being heat treated. the furnace being heated by any suitable and wellknown means, not shown, such as resistance heaters. The plates being heat treated are shown` supported by the cradle l which is suspended in the furnace at each end by the chains 5 extending up through the top and thence over the pulleys 8 to the winch 1. By means of the motor 8 the winch may be turned to raise and lower the cradle containing' the plates in a well understood manner.

The removable furnace bottom Il is shown yfulllinesinthedrawinginits position closingthebottomopeningofthefurnaceand ensaaingthebottomwallsthereofinamannerto sealthefurnace. Thebottom Ilissupportedby a carriage comprising the upper member II which is constructed to receive it and adiustably support it through the-adjusting screws I2 and the lower member I l which is provided vwith the wheels vIl arranged to run on the track Il supported by the I-beam Il. To maintain the two members II and I3 in proper relative horizontalV position they are provided with co-operating guides represented in the drawing as the guide not permitted to Projections I1 on the member II andthe cooperating arm I8 on the member It. When the carriageisin the position represented by i'ull lines in Fig. 1. the right-hand end oi' the lower member I3 is. in engagement with the stop 3d on the end o! the I-beam I.

The upper and lower members ii and I8 are connected 'together adjacent the lfour corners of the upper member by toggle Joint mechanism comprising four sets of toggle joint links 2l. The lower ends yof the links are pivoted upon the shafts 22 of the wheels It; the upperends oi the links are pivoted on the s tubv shafts 23 carried by tapering extensions of the upper'member II. The intermediate portions of the sets of toggle Joint links at the same end of the furnace are i connected together by the bar 24 so that th'ose toggle Joint links move in unison. Connected with opposite ends of the bar 24 is the chain 2B, the connection with the right-hand end of the bar being shown through the cushioning spring .2l in order to prevent damage to the mechanism by reason of overtravel of the chain after the carriage has reached the stop Inl. 'I'he operating chain 28 engages the idler sprocket 28 at one side of the furnace and the driving sprocket 2l at the other side thereof. The latter sprocket is arranged to be driven in one direction or the other by the motor Il through the reducing worm gear 3|. vArranged between the lower member I3 of the carriage and the bar Il thereoi' is the tension spring 32 whose function will appear later. The lower member Il of the car riage has an arm through which is threaded the limiting screw 3l which is arranged to engage one of the toggles to prevent it from passing over center when moved from the collapsed position to the straightened podtiom Preferably. this screw is so adiusted that the toggles are am quite reach a straightened p0- the furnace to a collapsed position as indicated by. dotted lines. As a result oi this movement of the toggle joint links the spring I2 is subjectv to greater tension, the force oi' which later serves determined by the stop 34. By this collapsing movement of the links the upper member H of the lcarriage and the furnace bottom lli move straight downward until further movement of the links is arrested by the stop 3l. Continued rotation of the driving sprocket 29 in the same direction results in a horizontal movement of lthe entire carriage with the bottom IU thereon until it has reached a point to the left of the track extending horizontally beneath the furnace, a carriage thereon including relatively movable upper and lower members, said upper member supporting said bottom, Atoggle joint mechanism connecting said members, force applying means connected with a part of said toggle joint mechanism and operative through said mechanism to move the carriage on the track limiting the movement of the carriage in one furnace, as seen in Fig. l, sumciently far re-" moved that it will not interferewiththe lowering of the charge.

After a new charge has been raised in the.

furnace the driving sprocket 29 is rotated in the carriage bodily to the right cilers less resistance than that offered by the raising of the upper member thereof by the toggle links the entire carriage and bottom will roll to the right until the bottom reaches a position directly beneath the furnace walls. In that position the stop arrests further movement of the carriage whereupon continued rotation of the driving sprocket ,opposite'fdirectiom Since movement of the forces the toggle links from the collapsed position to the straightened or nearly straightened position as determined by the limiting screw 33..

The movement of the upper member Il and hence cf the bottom ill as a result of straightening the toggle links is vertical, the bottom being brought up to firm or sealing engagement with the side walls of the furnace.

It will bey understood that the togglel joint mechanism, the operating chain, sprockets, etc.,

are duplicated at the opposite end of the furnace from that shown by Fig. l, the two driving sprockets being preferably secured to the same shaft so as to be driven by a single motor.

What I claim as new -and desire to secure by Letters Patent of the United States is:`

1. The combination with a lfurnace having side walls and a removable bottom comprising a track extending horizontally beneath the furnace, a carriage thereon including relativelyl movable upperA and lower members, said upper member supporting said bottom, forcerapplying means for moving said carriage horizontally on said track, a stop for limiting said horizontal movement of the lower member of said carriage, and means responsive to a continued application of force by said'means after the lower member has reached said stop for raising said upper member tc bring said bottom into engagement with the side walls of the furnace.

2. The combination with a furnace having sidewalls and a removable bottom comprising a with the upper member thereof lowered, and a stop arranged to engage said lower member for direction to a position in which'said bottom is in a predetermined position beneath the furnace. said mechanism being responsive to the continued application of force by said means to raise said upper member thereby to bring said bottom into engagement with said side walls. I

3. The combination with a furnace having side walls vand 'a removable bottom comprising a track. extending horizontally beneath the furnace, a carriage including a lower member mounted to roll on said track and an upper member arranged to support said bottom, cooperating vertical guide means on said members, toggle joint mechanism havingopposite ends connected with said members, means for applying force to the intermediate portion of said mechanism when the mechanism is relatively collapsed for moving the carriage on the track from a position laterally displaced from the furnace` to one beneath the same, and a stop for limiting the movement of the lower member of the carriage, the continued application of said force after the carriage has reached said stop causing said mechanism to straighten thereby causing said bottom to engage the side walls of the furnace.

4. The combination with.. a furnace having side walls and a removable bottom comprising a track extending horizontally beneath the furnace, a carriage including a lower member mounted to roll on said track and an upper memberarranged to support said bottom, cooperating vertical guide means on said members, toggle joint mechanism having opposite ends connected with said members and constructed to raise said upper member from a lowered position when the mechanism is moved from a partly collapsed position to a straightened position, a spring tendingto move said mechanism from said former position to said latter position, a motordriven chain connected with the intermediate part of said mechanism and a stop for limiting the movement of the lower member of said carriage in one direction on said track to a position in which said bottom is directly beneath said furnace.

ERNEST A. SMITH. 

